Array

Array Class

The Array class contains objects ordered by index from 0... n.

Instances of Array objects store unique copies of objects, so they can be added and deleted without worrying too much if an Array member is referred to by another object (unless the program later refers to the Array member; i.e., after it’s been stored with a method like atPut).

So most statements on Array members are safe, but you should be careful when using multiple Array operations in the same expression. For example, the following expression is not safe.

  myArray atPut 0, ((myArray at 0) - 3);

That’s because the atPut method replaces the element at 0 while the original element is still being used as an argument. It’s safer to use another object to work on an Array element.

  tmpInt = ((myArray at 0) - 3);
  myArray atPut 0, tmpInt;

Instance Variables

value

The value is the name of the array.

0... n

These instance variables refer to the elements of the array.

Instance Methods

= (Array a)

Set the receiver array’s elements equal to the argument array’s elements.

asString (void)

Returns the contents of the receiver Array as a String object. If any member of the receiver is a Character object, unquotes the Character object’s value and concatenates the character to the result string. Otherwise the method concatenates each of the receiver Array’s values into the result string.

at (int n)

Retrieve the nth element of the receiver array.

atPut (int index, OBJECT *item)

Add item to the receiver at index.

map (method)

Executes method with each element of the receiver.

The argument, method, is a method that should belong to the same class as the receiver. When method is executed, its receiver is each successive array element, and method can refer to it with self.

size (void)

Return the number of elements in the receiver.